Diferent issues on smoothing a mesh
There is one operator that allows you to what you did in the video in one single step and with greater control over the distance.

You can select all desired faces and use the Inset operator, i key by default. Do change the settings and tick the Individual option so each face is inset by itself.



That will however lead to "quad corner" based topology which while still being predominantly quad based is not great for subdivision, and doesn't work well with adding control edge loops.

What you can do in your case is use the Bevel operator instead, with the right settings it will give a quad dominant topology, and continuously flowing loops along the fuselage that will lead to less "rounded faces".

Make sure you select the whole edgeloops around the ship, set the number of segments to 2 and the Profile value to 1 to it keeps the original angle